The success of a smart phone in today's user world is dependent on 2 factors... O.S. flexibility and navigation useability, as well as hardware specifications. How a brand can outshine one another is a thing of the past... although most buyers are flocking towards the Samsung camp.
I myself will still stick to BlackBerry, although Windows Phones will still be my weekend sidekicks. In comparison, i will still prefer BB10 as the OS is flexible in accepting Android apps in contrast the Windows don't and pretty limited when comes to apps option.